Spark knock problem, tried the obvious, next steps?

[cbxer55]

Why would you delete the EGR and pay for 93 octane? EGR is only operational at smaller throttle openings, it basically doesn't hurt power at all.

According to my scanner, it was bad anyways. So i just removed it and the DPFE, and all the hoses. Yup, still have a code for it being gone. Yup, piece of black tape fixes it up swell. I removed in on my 04 Lightning to make spark plug changes on the driver's side easier. The damn tube blocked off the two back plugs. I also relocated the power steering reservoir off the top of the engine to a bracket I made to put it on the shroud. Makes getting to the front two plugs easier. I can now see all four COPS on the drivers and passenger side. Makes plug changes so much easier.

Deleting the EGR doesn't make the engine need 93 octane though. I know how they work. For whatever reason, I've replaced the stupid DPFE twice since I've owned the truck. Not again. Maybe it was just because the parts were made in mexico parts from Auto Zone? But twice for that stupid thing is twice too many.

 

[cbxer55]

My Ranger has pinged for years. At times it's been really bad. Maybe the Sea Foam just made it a little more easy to fix. There was a time, the only way I could get it to run without pinging was to run 93 octane and mix in some 110 octane Sunoco from the same station. That was the only way it would run ping free. I had no codes, and had replaced just about everything that could be replaced. Coils, plus, wires, sensors, etc. Still did it. Don't know what changed, but since around 2014, 93 by itself does the trick. Fuel pump croaked in 2016, so did a new one. Nothings different though.

I'm rather fortunate though. I'm single, have a good job that pays well. I never had a problem keeping a five gallon can of 110 octane in my garage, in case it was needed. Still do to this day. Get it from the same station that sells the 93 octane.

One day, I filled it up at a Shell station with V-Power 91. Pulled out of the lot, and just barely touched the petal, and it was pinging. Really bad (marbles in a tin can sound). Maybe the truck driver mixed up the stuff and put it in the wrong underground tank? Got home, topped up the tank with 110, and kept doing it every time I drove it, til the five gallons was gone and the pinging stopped. Haven't used 91 octane one time since then.

 

[RonD]

All exhaust has water vapor in it, its a by product of burning an air(O) fuel(H) mix, you get H2O, this is why exhaust parts rust from the inside out

This is also why DPFE sensors don't last very long, the two hoses have water vapor in them and DPFE cools off faster than engine/exhaust so water condense inside the sensor, eventually causing a failure
You can blow out the hoses every month or so to get DPFE to last longer but they will still eventually fail

 

[cbxer55]

All exhaust has water vapor in it, its a by product of burning an air(O) fuel(H) mix, you get H2O, this is why exhaust parts rust from the inside out

This is also why DPFE sensors don't last very long, the two hoses have water vapor in them and DPFE cools off faster than engine/exhaust so water condense inside the sensor, eventually causing a failure
You can blow out the hoses every month or so to get DPFE to last longer but they will still eventually fail

Far as I know, most of the aftermarket replacements are plastic, not metal. The two I bought were. But, I suppose there is still metal components inside them that can rust. I'm fortunate to live in a state that doesn't do smog checks or inspections. Just bought the 2007 Mustang in November. Not one thing, no inspection, no smog check. Drove to the Tag Agency, paid my money, got my one single license plate, walked out the door. Was only a tad under $300 for a newly purchased vehicle. They didn't even walk out the door and look to see if all the lights worked. LMAO. NICE!!

 

[8thTon]

Strange, my 2004 is the highest hp rated version and does not ping at all on 87 octane.

 

[cbxer55]

Strange, my 2004 is the highest hp rated version and does not ping at all on 87 octane.

Could it be that the later models have "Knock" sensors? My 98 doesn't. My 07 4.0 Mustang does. But guess what? With knock sensors, if they detect knock, they retard the timing. You lose power for it. WHen I bought the Mustang, it had a tankful of 87. Ran fine, didn't ping. First opportunity, I filled it with 93. Runs even better. Computer isn't retarding the timing due to bilge water in the gas tank.

 

[Dirtman]

Yes that's the point of a knock sensor, to get the maximum efficiency from an engine on the lowest octane fuel. No one in their right mind would want to buy a cheap pickup truck that needed high octane fuel to run. Only a couple years did 3.0s have a knock sensor for some unknown reason. The restrictive exhaust flow raises cylinder temps. So you have a high compression engine with high cylinder temps and no knock sensor, add carbon in the mix and it's a pinging machine.

 

[cbxer55]

Yes that's the point of a knock sensor, to get the maximum efficiency from an engine on the lowest octane fuel. No one in their right mind would want to buy a cheap pickup truck that needed high octane fuel to run. Only a couple years did 3.0s have a knock sensor for some unknown reason. The restrictive exhaust flow raises cylinder temps. So you have a high compression engine with high cylinder temps and no knock sensor, add carbon in the mix and it's a pinging machine.

My exhaust isn't restrictive. No muffler, two outlets in front of the passenger tire. Just the converters there to somewhat mute the sound. LMAO! Note the nice and black Lakewood slappers behind the tips. No more wheel hop. Unbelievable, but those are made by Lakewood especially for Rangers. Been on there since like 2002, when I also put on the rear Hellwig anti-sway bar.

Sure, it's loud. A friends dad likened it to sounding like it has a V-8 under the hood. He asked me that one day while it was sitting outside his machine shop idling. He came in and asked my what size V-8 it had under the hood. I LMAOed, and told him 3.0 V-6. Him, "sounds amazing."

 

[Dirtman]

The head is the restriction...

 

[cbxer55]

The head is the restriction...

I'll keep mine just the way it is. It's just fine. I have no issue with paying for 93 octane. I run it in all my vehicles. As you can see from my last post, it's not a bad looking truck. I get people trying to buy it from me all the time. But, it's not for sale and won't be. If, for whatever reason, I had to start selling my vehicles. It would be the last to go. B-King first, M109R second, Lightning third, Mustang fourth, Ranger last.

 

[RonD]

Restricted is the wrong word to use on a 4-stroke engine exhaust system, no 4-stroke engine runs better or has lower emissions with any exhaust restrictions
2-stroke does need restriction

All Rangers have tuned exhaust, for mid-range RPM band, the tuning gives the engine more power in the mid-RPM band from Scavenged power
Scavenged power comes from exhaust Velocity flowing from a smaller tube into a larger tube, it causes a pressure drop which PULLS exhaust from the cylinder which leaves more power on the crank because it didn't have to PUSH it out

Exhaust ports on the heads can be made smaller to increase the velocity as well, which also carries the heat farther done the exhaust system to warm up the Cats faster, which does lead to lower "cold engine" emissions

But there is no restriction, ever

Many have put larger exhaust pipes on the head of many different engines, this is where the MYTH of Back Pressure comes from
You would LOSE POWER with larger pipes because you lose the Velocity and the scavenged power it creates
Car makes have used scavenging exhaust manifolds since the 1950's, by late 1960's pretty much every engine had this
So people would do a custom "free flow" exhaust and lose power...............
"WTF, I lost power??!!!"
"This engine must need back pressure"
Nope, they just lost the extra power from the factory exhaust manifolds

Exhaust manifolds/headers, can be made for three RPM ranges, low, mid or high, but only one of them
Its a design based on alot of math, you can read up on it
And these can be made, and are made, for a specific RPM, the closer you are to that RPM the more scavenged power you gain, below or above that specific RPM
Racing engines use different headers for different tracks, based on the RPM they will try to keep the engine in during the race, which is also based on gearing and tires

 

[8thTon]

Could it be that the later models have "Knock" sensors? My 98 doesn't. My 07 4.0 Mustang does. But guess what? With knock sensors, if they detect knock, they retard the timing. You lose power for it. WHen I bought the Mustang, it had a tankful of 87. Ran fine, didn't ping. First opportunity, I filled it with 93. Runs even better. Computer isn't retarding the timing due to bilge water in the gas tank.

Mine has no knock sensor - not on the diagrams or parts listings, nor have I found one. Mine is unmodified and the parts work, so it runs as it was designed to.

Basically, if your engine needs over 87 to run without pinging there's something wrong with it, which is what the OP is trying to figure out on his.

 

[cbxer55]

Mine has no knock sensor - not on the diagrams or parts listings, nor have I found one. Mine is unmodified and the parts work, so it runs as it was designed to.

Basically, if your engine needs over 87 to run without pinging there's something wrong with it, which is what the OP is trying to figure out on his.

Yeah. I know this. But as I said, there isn't anything else I can replace. It's most certainly excessive carbon buildup after 22 years and 166,000 miles. Carbon buildup is a free compression ratio increase, in my book. As long as I'm willing to pay for and run the 93 octane, it's not a problem. I AM NOT GOING TO PULL THE ENGINE, OR TEAR IT APART TO FIX IT! End of discussion. It runs and runs GREAT! Why fix what isn't broken?

I don't care about the 93 octane. I use it in all five of the vehicles listed below in my signature line. Every tankful. It's not a problem. They all run GREAT! Not a one of them has ever pinged on me. Likely never will. I'm 58 years old and old school. Old school meaning I was taught, and believe, to always run the most octane you can do reasonably. Not including racing gas, which I always have a five gallon can of Sunoco 110 in my garage in any event.

I know what the OP is trying to do. I with him luck with it. I've done the ping battle, replace damn near everything road. Still pinged. It doesn't with 93 octane, so I will continue to use it. Just like I use 20w-50 oil in four of the five vehicles listed below. Only exception being the Lightning, which I use 10w-30, it's a 5w-20 vehicle. Never been a problem. Neither has the 20w-50 in the other vehicles. Old school. That's me. Always has been, always will be.

 

[8thTon]

I'm 58 years old and old school. Old school meaning I was taught, and believe, to always run the most octane you can do reasonably.

Well, I’m only 2 years younger, and that’s nothing I ever heard of. There is zero benefit to running more octane than you need, so I run the least octane that will work. If it really is carbon build up in the combustion chambers (speculation at this point), on a modern engine with feedback fuel injection that usually the result of something else that’s been malfunctioning for a while. 166k isn’t that extreme, and it sounds like yours has done this for a long time, so you might consider it’s from something else, like the mods on the efi system.

 

[Bgunner]

Well, I’m only 2 years younger, and that’s nothing I ever heard of. There is zero benefit to running more octane than you need, so I run the least octane that will work. If it really is carbon build up in the combustion chambers (speculation at this point), on a modern engine with feedback fuel injection that usually the result of something else that’s been malfunctioning for a while. 166k isn’t that extreme, and it sounds like yours has done this for a long time, so you might consider it’s from something else, like the mods on the efi system.

From Exxon but really they just want your money so take it for what it is, a brand's spin on it.

https://www.exxon.com/en/octane-rating
Octane ratings
Understanding octane ratings
About octane ratings
Octane rating is a measure of a fuel's ability to resist ‘knock.’ The octane requirement of an engine varies with compression ratio, geometrical and mechanical considerations, and operating conditions. The higher the octane number, the greater the fuel’s resistance to knocking or pinging during combustion.
The octane ratings of Synergy™ gasoline

• Synergy™ Regular Gasoline – Octane 87
• Synergy™ Extra Gasoline – Octane 89
• Synergy SUPREME+™ Gasoline – Octane 91-93

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This is from the U.S. Energy Information Administration And the one to read as the information is is much more in depth (EDIT: also was updated December 5th 2019 at teh time of this posting):

https://www.eia.gov/energyexplained/gasoline/octane-in-depth.php
What is octane?
In recent years, car manufacturers have been requiring or recommending premium gasoline (a high-octane grade of fuel) for use in more of their vehicle models. The difference in prices between premium and lower octane grades has also increased. As a result, more people are curious about what octane is and what those octane rating numbers on gas pumps mean.

Octane ratings are measures of fuel stability. These ratings are based on the pressure at which a fuel will spontaneously combust (auto-ignite) in a testing engine. The octane number is actually the simple average of two different octane rating methods—motor octane rating (MOR) and research octane rating (RON)—that differ primarily in the specifics of the operating conditions. The higher an octane number, the more stable the fuel. Retail gasoline stations in the United States sell three main grades of gasoline based on the octane level:

• Regular (the lowest octane fuel–generally 87)
• Midgrade (the middle range octane fuel–generally 89–90)
• Premium (the highest octane fuel–generally 91–94)

Some companies have different names for these grades of gasoline, such as unleaded, super, or super premium, but they all refer to the octane rating.